fix for start to non-gui system (QApplication)

main.cpp

@@ -16,7 +16,12 @@ int main(int argc, char *argv[])
         return 1;
     }
 
-    QApplication a(argc, argv);
+    // To start QApplication without X-server (non-GUI system) should use:
+    // "export QT_QPA_PLATFORM=offscreen" in plain shell
+    // or
+    // "Environment=QT_QPA_PLATFORM=offscreen" in systemd service ([Service] section)
+
+    QApplication a(argc, argv, false);
 
     QString configFile;
     for (int i = 1; i < argc; i++) {

systemd/ircabot.service

@@ -8,7 +8,9 @@ Type=idle
 User=USERNAME
 # Change paths to actual (like a /srv/ircabot or something):
 ExecStart=/path/to/ircabot -c /path/to/ircabot.conf
+# To run on non-GUI system:
+Environment=QT_QPA_PLATFORM=offscreen
 Restart=on-failure
 
 [Install]
-WantedBy=multi-user.target
+WantedBy=multi-user.target